Process for the separation of nickel and copper



Patented Nov. 26, 1940 FFICE Paocnss Fort THE snmaa'rron or met. AND cornea Guenther Hamprecht, Leo Schlecht, and Georg Tragcser, Ludwigshaien-on-the-Rhine,

Ger-

many, assisnors to I. G. Farbenindustrie Aktiengesellschai't, Frankfort-on-the-Main, Germany No Drawing. Application April 13, 1939, Serial No. 267,620. In Germany Aprii 26, 1935 Ores or other raw materials containing nickel and copper are usually worked up for the separation of the nickel from copper while first producing from the raw material a nickel-copper matte containing sulphur. The known methods for working up this matte, such as the top and bottom smelting process, or treatment with carbon monoxide for the purpose of forming nickel carbonyl, or roasting of the matte to oxides with subsequent dissolution of the copper oxide with sulphuric acid, either require a large number of working operations or, as in the case of the carbonyl process, large apparatus, so that the carrying out of the process is only economical on a comparatively large scale.

It has also been proposed to treat the nickelcopper matte in which the nickel and copper are mainly present as sulphides directly with an acid. By this method, however, either only a part of the nickel passes into solution or large amounts of copper are also dissolved. Since for economical reasons the nickel must be dissolved out as completely as possible, several working operations are also necessary in this case for the separation of the two metals, and this renders the process expensive.

We have now found that the nickel can be dissolved with acids with surprisingly good results when using a matte the sulphur content of which amounts to about a quarter of the copper con tent.

If the sulphur content be less, and a part of the copper is therefore present, not assulphide, but as metal, this amount or copper forms with nickel an alloy which is dificultly attacked by the acid and therefore only passes slowly into solution, while the part of the nickel is not dissolved or considerable amounts of copper pass into solu tion at the same time. If the matte contains more sulphur than corresponds to the ratio 1:4 relative to copper, little nickel again passes into solution and the copper content of the solution increases undesirably.

A further considerable advantage of using a matte the ratio of copper to sulphur oi which is about 4:1 lies in the fact that no hydrogen sulphide is developed in the treatment with acid. Furthermore, not only does the nickel pass into solution more completely, but also at a considerably greaterspeed. Theduration of the treatment is shortened and the apparatus for the process and the manipulation of the same are considerably simplified.

It is especially advantageous to keep the initial material; during the dissolving process, in suspension or, when it is present in too large particles therefor, in motion, as for example by stirring.

Hydrochloric and sulphuric acids are especially suitable as acids.

The following examples will further illustrate how the present invention may be carried out in practice, but the invention is not restricted to these examples.

Example 1 Percentage in the solution of- Nickel Copper Composition 0'! the motto 43.4 percent of Ni 92 45.9 percent of Cu 9.2 percent of 8 42.0 percent of Ni. 97 44.3 percent of Cu 12.2 percent of S .4 percent of NL percent of 011.

percent of S 3 percent of Ni 7 percent oi Cu percent of S Thus the solubility of the nickel is greatest and the solubility of the copper least at an approximate ratio of copperzsulphur of 5:1.

Example 2 25 kilograms each of nickel-copper mattes having dififerent sulphur content are treated for 2 hours at the boiling point with liters of a 20 per cent hydrochloric acid while stirring. After filtration, the nickel which has passed into solution is determined. The results are as follows:

Percentage of Ni in solution after 2 hours Ratio oi CuzS in the matte It will thus be seen that the speed of dissoluthe ratio sulphuric acid. 7

3. The process of recovering nickel apart from copper which consists in preparing a nickelcopper matte containing so much sulphur as corresponds to about one fourth of the copper content and treating said matte with an amount of hydrochloric acid necessary for the dissolution of the nickel content. a

Racer.

LEO i: or GEOBG mo. 

